I. Field Of The Invention
This invention relates to the construction field in general and has particular application to the erection of railings comprising top and bottom rails and spaced pickets extending therebetween. The assembly system, however, could also be used for erecting other types of structures having top and bottom members interconnected by a plurality of spaced elements extending between the two members, such as beams and studding.
II. Description Of The Prior Art
Railings have been provided in building structures for many centuries. Such railings ordinarily comprise a horizontally extending bottom rail and a parallel top rail spaced from the bottom rail, with a plurality of pickets, spindles or other vertical elements extending between the top and bottom rails, spaced from each other, and connected to the top and bottom rails at their respective ends.
In the days when most railings were made of wood, the ends of the pickets were doweled, and such doweled ends were inserted and secured in some manner in orifices provided in the rails. In some instances, the pickets might be secured to the top and bottom rails by means of screws or nails.
After the development of metallurgical techniques to the point where it became practicable to fabricate rails and pickets of metal, pickets have been secured at their ends to rails by a number of different methods, including force fits in orifices, catch locking, and by fastening with screws or bolts. Where the picket ends are force fitted into orifices in the rails, forging, machining or otherwise providing properly mating pickets and orifices can greatly raise the cost of fabricating metal railing systems. The same is also true where the orifices are provided with means to catch lock an appropriate configured end of the picket. Where railing systems are put together with screws or bolting, a considerable amount of labor may be required to produce each rail section. In relatively recent years, railing assemblies have been fabricated of aluminum in order to facilitate the shipping, handling and erection of the rail assemblies at the building sites. However, heretofore in order to provide the necessary resistance to bending forces which may be exerted by people coming in contact with aluminum railing assemblies, both the rails and the pickets, as well as the posts which support the rail assemblies, have been fabricated of fairly heavy gauge aluminum, particularly where it has been desired to have the rails rectangular in cross section, instead of circular, as with tubing. It has generally been considered more decorative to provide rails and pickets in a rectangular, rather than a tubular, construction. With the constantly rising price of aluminum, the cost of prior art aluminum rails, pickets and posts has continuously escalated to the point where many architects, in an effort to minimize costs of building construction, are being persuaded by their builders to minimize rail assembly use or to adopt less aesthetic tubular type railing systems.
There has existed, therefore, a considerable need for a relatively inexpensive rail assembly system utilizing a minimum of aluminum or other metal which can be put together and erected with a minimum of expensive labor.